package com.caifeng.mynotepad;


import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import java.util.ArrayList;
import java.util.List;

public class SQLiteHelper extends SQLiteOpenHelper {
    SQLiteDatabase sqLiteDatabase;

    //创建数据库

    public SQLiteHelper(Context context) {
        super(context, DBUtils.DATABASE_NAME, null, 1);
        sqLiteDatabase=this.getWritableDatabase();
    }


    //创建表
    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table " + DBUtils.DATABASE_TABLE + "(" + DBUtils.NOTEPAD_ID + " integer primary key autoincrement," + DBUtils.NOTEPAD_CONTENT + " text," + DBUtils.NOTEPAD_TIME + " text)");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
    //添加数据
    public boolean insertData(String userContent,String userTime){
        ContentValues contentValues=new ContentValues();
        contentValues.put(DBUtils.NOTEPAD_CONTENT, userContent);
        contentValues.put(DBUtils.NOTEPAD_TIME, userTime);
        return sqLiteDatabase.insert(DBUtils.DATABASE_TABLE,null,contentValues)>0;
    }
    //删除数据
    public boolean deleteData(String id){
        String sql=DBUtils.NOTEPAD_ID+"=?";
        String[] contentValuesArray=new String[]{String.valueOf(id)};
        return sqLiteDatabase.delete(DBUtils.DATABASE_TABLE,sql,contentValuesArray)>0;

    }
    //修改数据
    public boolean updateData(String id,String content,String useryear){
        ContentValues contentValues=new ContentValues();
        contentValues.put(DBUtils.NOTEPAD_CONTENT,content);
        contentValues.put(DBUtils.NOTEPAD_TIME,useryear);
        String sql=DBUtils.NOTEPAD_ID+"=?";
        String[] strings=new String[]{id};
        return sqLiteDatabase.update(DBUtils.DATABASE_TABLE,contentValues,sql,strings)>0;

    }
    //查询数据
    public List<NotepadBran> query(){
        List<NotepadBran> list=new ArrayList<>();
        Cursor cursor=sqLiteDatabase.query(DBUtils.DATABASE_TABLE,null,
                null,null,null,null,DBUtils.NOTEPAD_ID);
        if(cursor!=null){
            while(cursor.moveToNext()){
                NotepadBran noteInfo=new NotepadBran();
                String id=String.valueOf(cursor.getInt((cursor.getColumnIndex(DBUtils.NOTEPAD_ID))));
                String content=cursor.getString(cursor.getColumnIndex(DBUtils.NOTEPAD_CONTENT));
                String time=cursor.getString(cursor.getColumnIndex(DBUtils.NOTEPAD_TIME));
                noteInfo.setId(id);
                noteInfo.setNotepadContent(content);
                noteInfo.setNotepadTime(time);
                list.add(noteInfo);
            }
            cursor.close();
        }
        return  list;
    }



















}
